
35. Exposure to secondhand smoke can also increase your risk of cancer.
Even if you don’t smoke yourself, exposure to secondhand smoke can raise your cancer risk. There’s no safe level of exposure, and while most public places have banned smoking on the premises, it can be hard to avoid smoke in your home or at private gatherings. Being in the house of someone who smokes, even if they’re not actively smoking at the time, can still harm you; chemicals from cigarette smoke can stick around in furniture and carpets.

The best way to protect yourself from secondhand smoke is to avoid people who smoke or places that allow cigarette smoking. If it’s not possible to avoid smokers, educating them on the risk to you and themselves may convince them to drop the habit for good.